Yeah, you should adjust your BOWDEN cable. I believe you should loosen it a little bit. Do a SEARCH to find out more info.
Oil depends on your climate, if it gets real cold, use 0w30, or 10w 40 or 10w 50. But if you have climate like So CAL (never really gets below 40), then 10w 40 (or 50), or 20w 50 are good oils. If you are in the warmer climate, a thicker oil would be better... it might help reduce your oil leak.
2006 E350 w/ 155k miles (Daily Driver)
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)